Improve system security

Systemsicherheit [de]

Don't be a fucking idiot and then some

important: read [[setup-ssh]]!

Fail2ban

Prevent spam, DDoS or Brute Force attacks

$ sudo apt install fail2ban $ sudo systemctl enable fail2ban $ sudo systemctl start fail2ban

UFW Firewall

Essential commands

• ufw allow
• ufw deny
• ufw status
• ufw enable
• ufw default deny incoming
• ufw default allow outgoing
• ufw limit

Personally, I allow:

• 22/tcp SSH
• 25 SMTP
• 143 IMAP
• 420 SSH
• 443/tcp HTTPS

and deny

• 80/tcp HTTP <-- insecure

and set the standard: deny incoming, allow outgoing

Docker

is a special kind of fun and can be found here: [[container-apps-docker]]